A novel integrated microsystem for multiplex processing of encoded microbeads on a single microchip
is presented. Conventional bio-analysis of proteins and DNA requires a combination of different
techniques including: accurate delivery of reagents, mixing, then reaction at controlled temperature to
yield a detectable product. Standard laboratory bio-assays require intervention at several stages to
manipulate samples. Furthermore, ultra sensitive quantification with a colorimetric or fluorescent label
is required to obtain the necessary results. This process is time consuming and labour intensive.
However the new multiplex microsystem reported here enhances logical bio-assay development due to
the integration of a compact optical detection system with customized analysis software in an enclosed
microfluidic environment. The bioassay was realised by careful integration of a Peltier cell and
associated control electronics which enabled specific identification of a hybridized DNA sequence
from a 4 x 4 cDNA library at a fixed temperature of 42oC. The multiple fluorescence measurements of
complementary hybridised DNA at the surface of encoded microbeads was confirmed. Thus, the
complete integration of the different bio-assay components on a single multiplex assay platform
provides distinct advantages of reduced sample volume, rapid analysis and low cost.